The present invention involves electronic data processing, and more particularly concerns improved control of signal parameter values in a multimedia system having many different media sources feeding single system-presentation devices.
Personal computers are evolving in several different directions. One of those directions leads toward a larger system including multimedia inputs from many different sources, presented to a user--or a group of users simultaneously--through a set of system output devices which have a configuration similar to that of an entertainment center or a home theater. This type of personal computer converges the capabilities of previously separate systems into a single system having greater capabilities than the sum of its parts, and at the same time reducing cost by eliminating the duplication of components providing the same function in the separate systems. An example of such a "converged system" is the publicly available Destination.RTM. PC/TV system from Gateway 2000, Inc. This product permits a user to enjoy the capabilities of both a personal computer system and a high-quality television system at a lower total cost than that of two separate systems.
One of the advantages of a convergence system is the availability of enough computing power to integrate many media input devices, such as direct-broadcast satellite receivers, compact disc and digital video disc players, video cassette recorders, and cameras, and to control their functions from a single central point such as a remote keyboard.
One of the disadvantages of a convergence system is that the output signal of each media device has characteristics and parameter values that differ from those of other media devices. Although a television tuner and a video disc player may both have connectors labeled "line out," the video and audio voltage levels, contrast compression, frequency bandwidths, and other parameters or characteristics of the two signals are almost always different enough to produce noticeable--and often irritating--differences when a common audio or audio/video output device presents them to a user. A user may also wish to have different parameter values for different signals from the same device. For example, the sound level for movie channels of a satellite receiver will generally be higher than the level for a news channel.
Many computer systems, as well as other multiple-input systems, include controls for adjusting the parameters of the signal transmitted to the presentation devices, the display monitor and/or loudspeakers. However, these are "master" controls, which adjust the parameters to the same values for all input devices. When users switch to another source, they must adjust the parameters again for the second device.
Some media devices include manually adjustable controls, permitting a user to set the signal parameters from that device to values such that connecting multiple devices to a single presentation device does not produce an irritating jump when sources are switched.
Frequently, however, a user wishes to adjust the signal parameters of the current input device or channel, say to accommodate temporary changes in the program quality or viewing position, without altering the parameters for other input devices or other channels. Changing the parameters with master controls requires constant readjustment. Adjusting individual manual controls usually involves tricky adjustments in controls which are inconveniently positioned and whose locations have been forgotten. Moreover, adjusting such controls from an actual viewing position is much easier than when leaning over the rear of a large display monitor.